Gas-cleaning apparatus



G. WILHELMSSON ETAL 3,279,156

Oct. 18, 1966 GAS-CLEANING APPARATUS 2 Sheets-Sheet 1 Filed D60. 21,1964 INVENTORS. GUNNAR WILHELMSSON LENNART GUS TAVSSON ATTYS.

Oct. 18, 1966 G WILHELMSSON ETAL. 3,279,156

' GAS-CLEANING APPARATUS Filed Dec. 21, 1964 2 Sheets-Sheet 2 FIGZ.

uanu a INVENTORS; GUNNAR WILHELMSSDN LENNART' GUS TAVSSON ArTTYS.

United States Patent 3,279,156 GAS-CLEANING APPARATUS GunnarWiihelmsson, Vaxjo, and Lennart Gustavsson, Lockebo, Jonkoping, Sweden,assignors to Aktiebolaget Svenska Flaktfabriken, toclrhoim, Sweden FiledDec. 21, 1964, Ser. No. 419,786 Claims priority, application Sweden,Dec. 21, 1963, 14,4il4/63 Claims. (Cl. 55-223) The present inventionrelates to a device for cleaning gases and in particular for cleaninggases that are dust laden, the cleaning being carried out in a two-stageor twostep device.

Gas cleaners or separators of the type to which the present inventionrelates are preferably used in steel factories, foundry plants,workshops, mines, and the like. Their use is prevalent where the dryprocess ha proven unsatisfactory. The amounts of exhaust gases inestablishments of the above mentioned type are usually relatively largewith the result that the conventional apparatus for cleaning gases intwo steps were usually difficult to place and required too much space.

The present invention provides an arrangement for cleaning the gases intwo stages and comprises a casing accommodating a first section whereina liquid is added to and mixed with the inflowing gas for agglomeratingthe dust particles and a subsequent second section in which the dust andliquid particles accompanying the gas are separated, the arrangementincluding communication of the separators with a liquid tank.

The present invention provides a novel solution to the problem ofcombining the required means for the two cleaning steps in a compactunit of low mounting height which is adapted to fit easily into a plantand which is to be connected to the gas-producing apparatu without thenecessity of complicated additional duct work. Moreover, the cleaningdevice is assembled of standardized units in such a manner that one unitin the agglomerating section cooperates with a specific number ofseparators in the separating section.

According to the present invention there is provided a device forcleaning dust-laden gases including a casing having a first sectionwherein liquid is added to and mixed with a dust-laden gas foragglomerating the dust particles; a second section in which the dust andliquid particles are separated from the gas; and a liquid tankcommunicating with both said section; said agglomerating sectioncomprising an inlet chamber for said dust-laden gases; a plurality ofgas nozzles arranged in parallel in the lower end of said inlet chamberand being directed toward said liquid tank; said nozzles beingconstituted by convergent side walls terminating at their lower endswith inwardly directed throttling flanges; liquid supply chambersarranged on each side of each nozzle and being disposed paralleltherewith, liquid outflow openings in the upper ends of said chambersadapted to emit a film of liquid over the convergent side walls of saidnozzles and to flow downwardly therealong to said throttling flange;said separating section comprising a plurality of tubular cycloneseparators arranged in rows in alignment with said nozzles, the numberof separators in each row being sulficient to accommodate the flow fromone associated nozzle, each said separator including a gas inletcommunicating with the space above said liquid tank; a gas outlet ineach separator; a collecting chamber for the cleaned gas common to allof said separator outlets; said chamber being disposed above saidoutlets and being defined by a partition wall; an outlet in the lowerend of each separator for separating dust and liquid particles from saidgas; and a conveying pipe extending from "ice each lower outletdownwardly to terminate below the level of the liquid in said tank.

The invention will be described in detail with reference to theaccompanying drawing showing, by way of example, one ernbodimentthereof, in which:

FIG. 1 is a perspective view of apparatus embodying the presentinvention with portions broken away;

FIG. 2 is a sectional view taken on the line 22 of FIG. 1; and

FIG. 3 is a reduced sectional view taken on the line 33 of FIG. 2.

As shown in the drawing, the apparatus comprises a casing 1 enclosingcleaning and separating apparatus that is in communication respectivelywith an inlet 2 for the gas to be cleaned and an outlet 3 for thedischarge of the cleaned gas. The inlet 2 communicates with a chamber 4having an inspection port (not numbered), and the gases passingdownwardly through the chamber 4 are directed through a plurality ofparallel rectangular exhaust nozzles 5 which, in the illustratedembodiment, open directly to the liquid tank 6 placed in the lower endof the apparatus.

It will be seen that the nozzles 5 include convergent side walls 7 whichterminate at their lower ends with an inwardly directed flange 8 forthrottling the gases.

The upper ends of the nozzle side walls; 7 are connected to liquidsupply chambers 9 that are arranged in parallel with the nozzles, eachchamber 9 being provided with a row of outflow openings 110. The supplychambers 9 are connected to a common distribution line 20 which, bymeans of a pump 21, is supplied with liquid from the tank 6 in the lowerend of the apparatus. In order to obtain an effective and uniform liquiddistribution to the nozzles 5, the outflow openings 10 of the supplychambers 9 are preferably placed in the plane'upper surface of thechambers as shown.

It will be seen from the drawing that the embodiment illustratedincludes five banks of supply chambers with the three central banksbeing located between the side walls 7 of adjacent nozzles 5. In otherwords, aside from the supply chambers adjacent the outer walls of thecasing, the remaining supply chambers are each common to two adjacentnozzles.

The chambers 9 are provided on their upper surfaces with a bar 11 thatis turned on edge and which extends undulatory of the openings to ensurea uniform liquid distribution to both sides of each of the centralnozzles. Therefore, the cleaning liquid supplied through the openings 10is distributed half to one side and half to the other to provide adownward flow along the side walls 7 of the nozzles 5 in the form of afilm which completely covers the wall surfaces.

As the liquid film flows over throttling flange 8, it is caught by thedownward gas flow and atomized for effecting the agglomerating of thedust particles. The coarse dust particles and liquid drops areprecipitated when the gas gets into contact with the surface of theliquid in the tank 6 while the remaining gas is deflected and is causedto flow into the adjacent separation section 12.

The separation section comprises a plurality of upwardly extendingtubular cyclone separators 13 that are arranged in rows. Each row ofseparators 13 is in line with an associated nozzle 5. Each separator 13is provided with a tangential gas inlet 14 that communicates with thefree space between the nozzle opening between the flanges 8 and thesurface of the liquid in the tank 6, and to ensure uniform distributionof the gas from the agglomerating section between the individualseparator 13 in each row thereof, the separators 13 are arranged in astep fashion with their level decreasing from the agglomerating sectionin a progressive manner. It will be also 3 noted that each separator isprovided at its upper terminal end with a gas outlet which communicateswith a common collecting chamber 17 for the discharge through the outlet3 of the cleaned gas. The outlet chamber 17 includes a partition wall 16which is also formed in a step fashion, and an inspection port (notnumbered).

The bottom of each separator 13 is inclined toward a dust outlet 18which, in turn, is connected to 'an outlet pipe 19 that extendsdownwardly to terminate below the level of the liquid in the tank 6.Each tangential gas inlet 14 is located immediately above the bottom ofits associated separator.

In operation, the gases progress through the apparatus in the directionsindicated by the arrows A to F inclusive in FIG. 2. Dust-laden gasenters the chamber 4 through the inlet 2, as indicated at A, andprogresses downwardly through the nozzles 5, as indicated at B. A gascleaning liquid is pumped through the distribution line and into theassociated liquid supply chambers 9 and through the openings 10 in theupper ends thereof. The liquid then proceeds downwardly along the sidewalls 7 of the nozzles in the form of a film and as this film flows overthe throttling flange 8, it is intersected by the downward gas flow andis atomized thereby to gather the dust particles. As previouslymentioned, the coarser dust particles and liquid will drop straightdownwardly into the tank 6 whilst the remaining gas is deflected such asat arrow C to flow into the inlets 14 of the separators 13 as shown atD. In the cyclone separators, the clean gas swirls upwardly, and thedust and liquid particles remaining flow down through the outlets 18 andproceed downwardly through pipes 19 into the liquid in the tank 6 whilstthe cleaned gases enter the collecting chamber 17, as shown at E, andare exhausted, as shown at F, through the outlet 3. The dust particlesseparated in both the first and the second stages settle in the lowerend of the tank 6 where they accumulate and are picked up by a screwconveyor 22 thereby to be carried to a discharging elevator 23 to beremoved from the device.

What we claim is:

1. A device for cleaning dust-laden gases including a casing having afirst section wherein liquid is added to and mixed with a dust-laden gasfor agglomerating the dust particles; a second section in which the dustand liquid particles are separated; and a common liquid tank underlyingboth said sections; said agglomerating section comprising (a) an upperinlet chamber for said dust-laden gases;

(b) a plurality of gas nozzles arranged in parallel in the lower end ofsaid inlet chamber and being directed toward and spaced above the liquidlevel in said tank;

(c) said nozzles having an opening in form of a rectangular slot andbeing constituted by convergent side walls terminating at their lowerends in throttling flanges directed inwardly of said opening;

(d) liquid supply chambers arranged on each side of each nozzle andbeing disposed parallel therewith;

(e) liquid outflow openings in the upper ends of said chambers adaptedto emit a film of liquid over the convergent side walls of said nozzlesand to flow downwardly therealong to said throttling flange; saidseparating section comprising (f) a plurality of tubular cycloneseparators arranged in rows in alignment with said nozzles, the numberof separators in each row being sufficient to accommodate the flow fromone associated nozzle;

(g) each said separator including a lower gas inlet communicating withthe space between said nozzle openings and said liquid tank;

(h) an upper gas outlet in each separator;

(i) a collecting chamber for the cleaned gas common to all saidseparator outlets; said chamber being disposed above said outlets andbeing defined by a partition wall;

(j) an outlet in the bottom of each separator for receiving dust andliquid particles separated from said gas therein; and

(k) a conveying pipe extending from each bottom outlet downwardly toterminate below the level of the liquid in said tank.

2. A device according to claim 1 including pump means connected to saidliquid tank and a common distribution line interconnecting said pumpwith each liquid supply chamber of the agglomerating section.

3. A device according to claim 1 wherein said chambers have plane uppersurfaces located between the nozzles and common to two adjacent nozzles;the outflow openings of the liquid supply chambers being disposed insaid upper surfaces; each said upper surface being provided with a barturned on edge and extending undulatory between the outflow openings forensuring a uniform liquid distribution to the walls of the nozzles onboth sides of each chamber.

4. A device according to claim 1, wherein the tubular separators locatedin each row are arranged in a stepped manner, the level of the gasinlets thereof decreasing stepwise from the level of the nozzles in theagglomeration section toward the level of the liquid in the tank, andwherein the partition wall which defines the collecting chamber and intowhich the clean gas outlets open has a similarly stepped configurationat the level of said upper inlet chamber.

5. A device according to claim 2, wherein the separators are providedwith a bottom inclined toward the bottom outlet and with a tangentialgas inlet located immediately above the said bottom.

References Cited by the Examiner UNiTED STATES PATENTS 2,899,183 8/1959Umbricht et al. 2611 12 X 3,061,994 11/1962 Mylting 346 3,085,793 4/1963Pike et al 2611 12 3,131,237 4/1964 Collins 55257 X 3,138,442 6/1964Krantz 55235 X 3,142,548 7/1964 Krantz 5589 3,171,401 3/1965 McDuffee26197 X FOREIGN PATENTS 1,107,647 5/1961 Germany.

15,225 7/ 1901 Great Britain. of 1901 ROBERT F. BURNETT, PrimaryExaminer. D. K. DENENBERG, Assistant Examiner.

1. A DEVICE FOR CLEANING DUST-LADEN GASES INCLUDING A CASING HAVING AFIRST SECTION WHEREIN LIQUID IS ADDED TO AND MIXED WITH A DUST-LADEN GASFOR AGGLOMERATING THE DUST PARTICLES; A SECOND SECTION IN WHICH THE DUSTAND LIQUID PARTICLES ARE SEPARATED; AND A COMMON LIQUID TANK UNDERLYINGBOTH SAID SECTIONS; SAID AGGOLMERATING SECTION COMPRISING (A) AN UPPERINLET CHAMBER FOR SAID DUST-LADEN GASES; (B) A PLURALITY OF GAS NOZZLESARRANGED IN PARALLEL IN THE LOWER END OF SAID INLET CHAMBER AND BEINGDIRECTED TOWARD AND SPACED ABOVE THE LIQUID LEVEL IN SAID TANK; (C) SAIDNOZZLES HAVING AN OPENING IN FORM OF A RECTANGULAR SLOT AND BEINGCONSTITUTED BY CONVERGENT SIDE WALLS TERMINATING AT THEIR LOWER ENDS INTHROTTLING FLANGES DIRECTED INWARDLY OF SAID OPENING; (D) LIQUID SUPPLYCHAMBERS ARRANGED ON EACH SIDE OF EACH NOZZLE AND BEING DISPOSEDPARALLEL THEREWITH; (E) LIQUID OUTFLOW OPENINGS IN THE UPPER ENDS OFSAID CHAMBERS ADAPTED TO EMIT A FILM OF LIQUID OVER THE CONVERGENT SIDEWALLS OF SAID NOZZLES AND TO FLOW DOWNWARDLY THEREALONG TO SAIDTHROTTLING FLANGE; SAID SEPARATING SECTION COMPRISING (F) A PLURALITY OFTUBULAR CYCLONE SEPARATORS ARRANGED IN ROWS IN ALIGNMENT WITH SAIDNOZZLES, THE NUMBER OF SEPARATORS IN EACH ROW BEING SUFFICIENT TOACCOMMODATE THE FLOW FROM ONE ASSOCIATED NOZZLE; (G) EACH SAID SEPARATORINCLUDING A LOWER GAS INLET COMMUNICATING WITH THE SPACE BETWEEN SAIDNOZZLE OPENINGS AND SAID LIQUID TANK; (H) UN UPPER GAS OUTLET IN EACHSEPARATOR; (I) A COLLECTING CHAMBER FOR THE CLEANED GAS COMMON TO ALLSAID SEPARATOR OUTLETS; SAID CHAMBER BEING DISPOSED ABOVE SAID OUTLETSAND BEING DEFINED BY A PARTITION WALL; (J) AN OUTLET IN THE BOTTOM OFEACH SEPARATOR FOR RECEIVING DUST AND LIQUID PARTICLES SEPARATED FROMSAID GAS THEREIN; AND (K) A CONVEYING PIPE EXTENDING FROM EACH BOTTOMOUTLET DOWNWARDLY TO TERMINATE BELOW THE LEVEL OF THE LIQUID IN SAIDTANK.